A cough of 10 days and more is quite common after a viral throat infection. Its called post viral cough. It is a self limiting cough and may take 2-3 weeks to resolve, provided his chest is clear and there is no sign of any chest infection or wheezing per se. Although he needs to be thoroughly examined before prescribing anything else, he can be given syp Honituss 5 ml twice a day, along with Nasoclear nasal drops before sleep. And do follow me after his chest and throat check up from a local Pediatrician.